The study revisits the theoretical models of the boundary layer suction on a flat plate using the numerical tool, XFOILSUC. The theoretical critical suction coefficient and the asymptotic suction profile was compared with the numerical results. Pressure drop through micro-perforated porous surfaces were measured for two cases - 1) Without boundary layer 2) With boundary layer. The measured pressure drop was then compared to the semi-empirical Bohning-Doerffer (B-D) model. The B-D model was not able to accurately predict the pressure drop for all the porous metallic samples measured and therefore corrections to the model were proposed. The aerodynamic porosity was found to vary as a function of hole velocity and diameter for a hole Reynolds number less than 200. Analysis of the maximum suction threshold was carried out using 2D numerical computation by introducing a semi-circular suction roughness element on the flat plate based on the suction coefficient. The qualitative method showcased that above a Reynolds number based on the radius of semi-circle suction roughness element of 160 the suction induced roughness might negatively affect the laminar flow on the flat plate.
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